Abstract: Three deuterated 3-and 4-methylcyclohexanones, 3, 4, and 5, have been prepared and photolyzed in methanol along with their unlabeled counterparts, 1 and 2. Irradiation of 1 leads to aldehyde 22 and ester 23; irradiation of 2 yields all four a-cleavage products, aldehydes 24 and 25 plus esters 26 and 27. The deuterium distribution in 22 and 24 from 3, 4, and 5 indicates that approximately two-thirds of the aldehydic hydrogen was originally ...
